It is well-known that in all the fields of surgery one tries to realize equipment that allows one to operate to a greater precision, and, moreover, allows surgeons without a great deal of experience to carry out delicate operative surgeries.
This is even more true in those fields wherein delicate organs are operated upon, and therefore there is particularly felt a need for such a device in ophthalmological surgery.
In this field, a very important operation consists in lamellar refractive surgery (keratomyleusis).
Keratomyleusis is a surgical methodology well known to those skilled in the art, originally set forth by Prof. Barraquer.
It has developed during years through three techniques, and the relevant apparatuses have been realized by Barraquer himself, by Krumeich and Swinger and then by Ruiz.
Among the various equipment that makes up the set of the surgical instruments necessary to operate, Barraquer's technique provides the use of a sucking metal ring which is applied on the eye of the patient and whereon the microkeratome slides.
In order to be able to achieve the exact keratic surface protrusion it is necessary to have a complete set of sucking metal rings at one's disposal.
Before carrying out the operation, one measures the intraocular pressure caused by the ring and measures, by means of a precalibrated lens, the lenticule diameter that would be obtained with that particular ring.
Only after verifying these variables and selecting the proper ring, will one be able to proceed to sectioning of the lamella.
Obviously, all these operations render the operation more difficult, less safe and longer.
In the techinque described by Krumeich and Swinger the same type of sucking rings is employed.
In Ruiz's technique, on the contrary, a series of pneumatic rings is employed which present the same already mentioned problems.
Recently, in the Application for Italian Patent No. 48104-A/89 filed on Jun. 21, 1989, an apparatus set has been suggested for carrying out myopical or hypermetropical keratomyleusis wherein a single sucking ring endowed with an adjustment ferrule is provided, for determining the diameter of the flap to be removed, and constituting a track for the sliding of the microkeratome and the precalibrated lens.
As is apparent, such a solution constitutes a considerable progress in comparison with the preceding apparatuses in that it allows one to rapidly determine the diameter of the flap to be removed, to measure intraocular pressure and to carry out the refractive section.
Subsequently, it has been suggested, by the same Applicant, a further improvement of the latter apparatus, and particularly a sucking ring realized with extremely simple mechanics, with a handle that allows a very safe positioning of the ring on the eye of the patient is able to effect decisively considerable excursions both downward and upward.
All that has been disclosed above has allowed the operation technique to be more and more improved. However, each of the improvement techniques described above maintains a very strict link between the result of the operation and the ability of the surgeon.
This is true in that the result is strictly connected with the ability of the surgeon.
Moreover, with these apparatuses of the manual type, it turns out to be very difficult to have a high repeatability of the operation.